{
  "summary": [
    "pbl_domain_ref",
    "world/scene/entity 薄扩展关联表（M8，不改基表）",
    "id",
    "记录复用平台 world/scene/entity 基表记录与 PBL 租户/蓝图/班级/团队的关联；基表无 tenant_id，PBL 多租户隔离由本表补齐。UNIQUE(tenant_id,ref_type,ref_id)。权威 DDL：data-model.md §J1；表总账：pbls_spec.json tables_by_module.pbl_domain_ext=1、tables_total=36。"
  ],
  "fields": [
    {"name": "id", "type": "bigint", "primary": true, "autoincr": true, "notnull": true, "comment": "主键"},
    {"name": "tenant_id", "type": "varchar(64)", "notnull": true, "comment": "租户ID（PBL 多租户隔离维度，基表无此列）"},
    {"name": "ref_type", "type": "varchar(32)", "notnull": true, "comment": "appcodes:pbl_domain_ref_type(world/scene/entity)"},
    {"name": "ref_id", "type": "bigint", "notnull": true, "comment": "复用基表记录ID（world.id / scene.id / entity.id）"},
    {"name": "blueprint_id", "type": "varchar(64)", "notnull": false, "comment": "关联蓝图ID（pbl_compiler apply_game_definition 落库后回写）"},
    {"name": "class_id", "type": "varchar(64)", "notnull": false, "comment": "关联教学班ID（pbl_governance.pbl_class）"},
    {"name": "team_id", "type": "varchar(64)", "notnull": false, "comment": "关联团队ID（pbl_governance.pbl_team，共享世界成员分组）"},
    {"name": "ext", "type": "json", "notnull": false, "comment": "扩展属性（JSON，薄扩展附加维度，禁止改基表结构）"},
    {"name": "is_deleted", "type": "tinyint", "notnull": true, "default": "0", "comment": "软删标记：0=有效 1=已解绑（unbind_ref 置 1）"},
    {"name": "created_at", "type": "timestamp", "notnull": true, "default": "CURRENT_TIMESTAMP", "comment": "创建时间"},
    {"name": "updated_at", "type": "timestamp", "notnull": true, "default": "CURRENT_TIMESTAMP", "comment": "更新时间（ON UPDATE CURRENT_TIMESTAMP）"}
  ],
  "indexes": [
    {"name": "PRIMARY", "fields": ["id"], "unique": true, "primary": true},
    {"name": "uk_pbl_domain_ref", "fields": ["tenant_id", "ref_type", "ref_id"], "unique": true, "comment": "设计 §2：UNIQUE(tenant_id,ref_type,ref_id)"},
    {"name": "idx_pbl_domain_ref_bp", "fields": ["tenant_id", "blueprint_id"], "unique": false, "comment": "按蓝图查关联（compiler/analytics）"},
    {"name": "idx_pbl_domain_ref_class", "fields": ["tenant_id", "class_id"], "unique": false, "comment": "按教学班查关联（F-AS-03 班级维度）"},
    {"name": "idx_pbl_domain_ref_team", "fields": ["tenant_id", "team_id"], "unique": false, "comment": "按团队查关联（US-13 共享世界分组）"},
    {"name": "idx_pbl_domain_ref_type", "fields": ["ref_type", "ref_id"], "unique": false, "comment": "悬挂引用一致性检查（左连接基表）"}
  ],
  "codes": [
    {
      "code": "pbl_domain_ref_type",
      "name": "域扩展关联类型",
      "owner": "pbl_appcodes",
      "items": [
        {"value": "world", "label": "世界（复用基表 world）"},
        {"value": "scene", "label": "场景（复用基表 scene）"},
        {"value": "entity", "label": "实体（复用基表 entity）"}
      ],
      "note": "编码由 pbl_appcodes 模块幂等注入，本模块只读引用，不重复写入编码表"
    }
  ]
}